The number of neutrons N = A - Z = 23 - 11 = 12 neutrons. There are no electrons in the nucleus of a sodium atom. There are 11 protons, 12 neutrons and 0 electrons inside a sodium nucleus.

This energy level model shows two electrons on the first energy level and six electrons on the second energy level. Since this atom has a total of eight electrons ... goes into the third level. 3rd ...